Tap size 2-56UNC for 6Al-4V ?

[HgRyu]

My machine shop tried to make taps for size 2-56 UNC screw on 6Al-4V but failed.
Is there any special super hard tap for 6Al-4V and where can I buy it ?

Thanks.

 

[dom]

Hi HgRyu
How big is that tap?
I looked at some chart and it said 1.7mm

That can't be right though ,can it?

I have used form taps from Titex in M6 and larger ,but never in titanium ,only
stainless,and they worked OK.

Much easier to get out if they ever broke anyway.

Cheers
Dom

 

[fludunlimited]

I use a 5/64 drill bit and a thread forming tap.
a tapping head helps alot to.

 

[precisionworks]

Balax Thredfloer (forming tap) works well in every material I've tried. Hole sizing is critical, you have to use their catalog to find the tap hole size. For 2-56, with 75% thread, the correct hole size is .078".

 

[KC2IXE]

...snip...I looked at some chart and it said 1.7mm

That can't be right though ,can it?

...snip...

2-56? 1.7mm? About right - they are SMALL - then again, somewhere downstairs I have a 000-120 tap - THAT is small. I've never used it - I basically was able to get it free, so I took it home as a "see how snall they get" showoff tool

 

[octaf]

HgRyu, I really hope you make it happen !!! :twothumbs

 

[HgRyu]

Thanks for all your kind comments.

 

[Ray1968]

I work for an aerospace company in Southern California. We drill and tap quit a bit of 6Al-4V for an F-22 component. The taps we use are made by Emuge, and according to our CNC programmers they work amazingly better than all the other brands we've tried (and we've tried a lot over the years).

If you're still interested I can get the exact info tomorrow. They're not cheap though. Expect to spend around $20-30 USD per tap I believe.

 

[precisionworks]

That's a nice tool selector chart on the Emuge site. No surprise that they also recommend a thread forming tap instead of a thread cutting tap.

My SWAG on forming vs cutting (in Ti) is that the forming tap has a larger total contact area, and dissipates better the heat buildup that happens with all Ti machining.

A cutting tap would concentrate the heat at the cutting face. If you figure that a 4-flute tap has about 50% flute area, almost all of the frictional & shearing heat is concentrated in four relatively small areas.